The web-push API in the browsers today. And has its first tests mastered, but there is still room for clarification. First we need to light the shade on what the web push actually is.
With web push the user can get informed about updates on a website or web application. As the user, you don't need have that page open. The notification can contain any kind of information that is interesting to the app. In a social media app a private message can be send to the users device via web push. An online shop might want to inform about the availability of a new product. A blog or news page can let you know about new posts and articles.